A Proxy Attack is a method of cyberwarfare where the attacking system impregnates the enemy system, intercepting and compromising communications.
Cyberwarfare is the use of information warfare for political means. With battlefields becoming increasingly dependent on technology, cyberwarfare is designed to mitigate such a force multiplier for the enemy.
Proxy Attack is a "Default Loop" commander resource that prevents the enemy commander from taking action for 15 seconds by interfering with their connection to ground forces. The enemy commander can still use satellite view and track the progress of individual soldiers, but cannot use any resources for the duration of the attack. In-game, voice chat between the commander and squad leaders is affected, rendering squad leaders and commanders unable to speak to each other for the duration of the proxy attack. Ground units are also alerted to the disruption by voice prompts.
Proxy Attack will also clear any deployed resources, even going so far as to eject gunners from Gunships. Proxy Attack takes a considerable amount of time to recharge, typically only usable two to three times in a match of one of the longer game modes, such as Conquest.
— Version 2.0 In-Game Description
Trojan is a hacker resource featured in Battlefield Hardline. It functions in a similar manner to the Proxy Attack resource from Battlefield 4, temporarily stopping all actions by the enemy Hacker as well as increasing friendly interaction with resources. Upon unlocking version 2.0, the duration of the resource is increased from normal.